(1R,4S,5S)-1-methyl-4-<(pivaloyloxy)methyl>-3-oxabicyclo<3.3.0>oct-7-ene-2,6-dione | 163728-79-8

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 内酯类
• 英文名称: (1R,4S,5S)-1-methyl-4-<(pivaloyloxy)methyl>-3-oxabicyclo<3.3.0>oct-7-ene-2,6-dione
• 英文别名: [(1S,3aR,6aS)-3a-methyl-3,6-dioxo-1,6a-dihydrocyclopenta[c]furan-1-yl]methyl 2,2-dimethylpropanoate
• CAS: 163728-79-8
• 化学式: C₁₄H₁₈O₅
• 分子量: 266.294
• InChiKey: BXXAJSQNLKFFCN-GPCCPHFNSA-N

物化性质

• 沸点：
  410.3±45.0 °C(predicted)
• 密度：
  1.198±0.06 g/cm3(Temp: 20 °C; Press: 760 Torr)(predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  1.6
• 重原子数：
  19
• 可旋转键数：
  4
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.64
• 拓扑面积：
  69.7
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  (1R,4S,5S)-1-methyl-4-<(pivaloyloxy)methyl>-3-oxabicyclo<3.3.0>oct-7-ene-2,6-dione 在 sodium tetrahydroborate 、 sodium periodate 、 cerium(III) chloride 、 copper(I) bromide dimethylsulfide complex 、 二甲基硫 、 碳酸氢钠 作用下， 以 甲醇 为溶剂， 反应 14.0h， 生成 (1S,4S,5R,6S)-6-hydroxy-8-isopropyl-1-methyl-4-<(pivaloyloxy)methyl>-3-oxabicyclo<3.3.0>oct-7-en-2-one
  参考文献：
  名称：

  Novel Total Synthesis of (+)-Eremantholide A

  摘要：

  Stereoselective total synthesis of (+)-eremantholide A (1), a cytotoxic furanoheliangolide sesquiterpene, was accomplished in an enantiospecific fashion. The total synthesis featured the following three key synthetic strategies. (1) Intramolecular cyclization of carbon-radicals derived from xanthates 19a or 19b proceeded regio- and stereoselectively in an exclusive 5-exo-dig mode to provide bicyclic lactones 20a or 20b. Further functional group manipulations of 20a and 20b efficiently afforded a highly substituted 3,7-dioxabicyclo[3.3.0]octan-2-one derivative 34, which served as a synthetic equivalent to the A/B ring system in 1. (2) Alkylation of the enolate of 3(2H)-furanone 36 with triflate 35 was thoroughly investigated to maximize formation of the C-alkylated diastereomers, either 10R-isomer 37 or 10S-isomer 38. It was found that choice of the base, solvent, and/or additive was critical to the diastereoselectivity. Furthermore, the 10R-isomer 50 was also prepared in increased yield and improved diastereoselectivity by coupling 36 with A/B ring equivalent 49. (3) In a later stage of the total synthesis, construction of the strained 11-oxabicyclo-[6.2.1]undeca-2,10-dien-9-one system (the C/D ring) was accomplished by means of an intramolecular vinylogous aldol reaction of aldehyde 52, prepared from 10R-isomer 40, followed by base-catalyzed beta-elimination of the corresponding mesylates 54. On the other hand, by employing analogous reaction conditions, the 10S-isomer 56 was transformed into unnatural (-)-10-epi-eremantholide A (61).

  DOI：

  10.1021/jo00130a017
• 作为产物：
  描述：

  [(2R,3S,4R)-3-formyloxy-5-hydroxy-4-[(1R)-1-methoxybut-3-ynyl]-4-methyloxolan-2-yl]methyl 2,2-dimethylpropanoate 在 咪唑 、 偶氮二异丁腈 、 三正丁基氢锡 、 sodium hydride 、 臭氧 、 1,8-二氮杂双环[5.4.0]十一碳-7-烯 、 三乙胺 、 三苯基膦 、 pyridinium chlorochromate 作用下， 以 四氢呋喃 、 甲醇 、 二氯甲烷 、 甲苯 、 paraffin 、 苯 为溶剂， 反应 12.08h， 生成 (1R,4S,5S)-1-methyl-4-<(pivaloyloxy)methyl>-3-oxabicyclo<3.3.0>oct-7-ene-2,6-dione
  参考文献：
  名称：

  Novel Total Synthesis of (+)-Eremantholide A

  摘要：

  Stereoselective total synthesis of (+)-eremantholide A (1), a cytotoxic furanoheliangolide sesquiterpene, was accomplished in an enantiospecific fashion. The total synthesis featured the following three key synthetic strategies. (1) Intramolecular cyclization of carbon-radicals derived from xanthates 19a or 19b proceeded regio- and stereoselectively in an exclusive 5-exo-dig mode to provide bicyclic lactones 20a or 20b. Further functional group manipulations of 20a and 20b efficiently afforded a highly substituted 3,7-dioxabicyclo[3.3.0]octan-2-one derivative 34, which served as a synthetic equivalent to the A/B ring system in 1. (2) Alkylation of the enolate of 3(2H)-furanone 36 with triflate 35 was thoroughly investigated to maximize formation of the C-alkylated diastereomers, either 10R-isomer 37 or 10S-isomer 38. It was found that choice of the base, solvent, and/or additive was critical to the diastereoselectivity. Furthermore, the 10R-isomer 50 was also prepared in increased yield and improved diastereoselectivity by coupling 36 with A/B ring equivalent 49. (3) In a later stage of the total synthesis, construction of the strained 11-oxabicyclo-[6.2.1]undeca-2,10-dien-9-one system (the C/D ring) was accomplished by means of an intramolecular vinylogous aldol reaction of aldehyde 52, prepared from 10R-isomer 40, followed by base-catalyzed beta-elimination of the corresponding mesylates 54. On the other hand, by employing analogous reaction conditions, the 10S-isomer 56 was transformed into unnatural (-)-10-epi-eremantholide A (61).

  DOI：

  10.1021/jo00130a017

文献信息

• A total synthesis of (+)-eremantholide A
  作者：Ken-ichi Takao、Hiroshi Ochiai、Takahiko Hashizuka、Hirokazu Koshimura、Kin-ichi Tadano、Seiichiro Ogawa

  DOI：10.1016/0040-4039(95)00066-l

  日期：1995.2

  Stereoselective and enantiospecific total synthesis of (+)-eremantholide A (1) is described. The present total synthesis features 1) regio- and stereoselective radical carbocyclization of D-glurose-derived gamma-lactone 7, and 2) a nine-membered ring formation by the coupling reaction of bicyclic triflate 18 and known furanone 19 followed by a vinylogous aldol reaction.
• Novel Total Synthesis of (+)-Eremantholide A
  作者：Ken-ichi Takao、Hiroshi Ochiai、Ken-ichi Yoshida、Takahiko Hashizuka、Hirokazu Koshimura、Kin-ichi Tadano、Seiichiro Ogawa

  DOI：10.1021/jo00130a017

  日期：1995.12

  Stereoselective total synthesis of (+)-eremantholide A (1), a cytotoxic furanoheliangolide sesquiterpene, was accomplished in an enantiospecific fashion. The total synthesis featured the following three key synthetic strategies. (1) Intramolecular cyclization of carbon-radicals derived from xanthates 19a or 19b proceeded regio- and stereoselectively in an exclusive 5-exo-dig mode to provide bicyclic lactones 20a or 20b. Further functional group manipulations of 20a and 20b efficiently afforded a highly substituted 3,7-dioxabicyclo[3.3.0]octan-2-one derivative 34, which served as a synthetic equivalent to the A/B ring system in 1. (2) Alkylation of the enolate of 3(2H)-furanone 36 with triflate 35 was thoroughly investigated to maximize formation of the C-alkylated diastereomers, either 10R-isomer 37 or 10S-isomer 38. It was found that choice of the base, solvent, and/or additive was critical to the diastereoselectivity. Furthermore, the 10R-isomer 50 was also prepared in increased yield and improved diastereoselectivity by coupling 36 with A/B ring equivalent 49. (3) In a later stage of the total synthesis, construction of the strained 11-oxabicyclo-[6.2.1]undeca-2,10-dien-9-one system (the C/D ring) was accomplished by means of an intramolecular vinylogous aldol reaction of aldehyde 52, prepared from 10R-isomer 40, followed by base-catalyzed beta-elimination of the corresponding mesylates 54. On the other hand, by employing analogous reaction conditions, the 10S-isomer 56 was transformed into unnatural (-)-10-epi-eremantholide A (61).